Denture.



N0- 830,887. PATENTED SEPT. 11, 1906. R. M. CRAIG.

DENTURB.

APPLICATION FILED JAN.17, 1906 p I no.1 $303,887.

' To all; whom it may concern.-

UNITE-D STATES- PATENT OFFIC eoBn TMEADE cRAIQ .oF DENNISON, OHIO.

.DENT.URE.'

Be it known that I, ROBERT MEADE CRAIG,

a citizen: ofithe United States, and a resident of Dennisonginthe county of- Tuscarawas and State of Ohio, have invented a new and usefuilmproveme'nt in Dentures, of which the following is a full, clear, and exact description.

The purpose of the invention is to provide aporcelain tooth or facing so shaped that the backing can be quickly and conveniently applied thereto and readily set to the tooth in such manner as toibe a fixture therein and .;;wl'1ei ei-11" the backing when in. position will. be

hidden from sight .at thefront of the body.

A further purpose of the invention is-to= provide a backing which is practically keyed to the porcelain and which may be utilized in plate, bridge, or other dental work where a tooth is to be affixed to an object.

A further purpose of the invention is to so construct the backing that the porcelain may be removed therefrom. without necessitating the removal of the entire denture, thus admi tting of ready repair. 7

'Another purpose of the invention is to provide a backing of the character described equally applicable to incisors, canines, bicuspids, or molars.

'lhe invention consists in the novel constructionand combination of the several parts,

as will be hereinafter fully set forth, and pointed out in the claims. Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the fig ures.

Figure 1 is a perspective view of a porce lain bicuspid and the backing applied therea to. Fig. '2 is a perspective viewof the bicusbacking.

pid with the backing removed. Fig. .3 is a perspective view of the backing for the bicuspid. Fig. 4 is an enlarged horizontal section through the porcelain bicuspid and its Fig. 5 is a'perspective view of an incisor with the backing applied. Fig. 6 is a perspective view of the incisor with the backing removed. Fig. 7' is a vertical section through the incisor and its backing, drawn upon a smaller scale, the section being taken practically on the line 7 7 of Fig. 9. Fig. 8 is a front elevation of the backing. Fig. 9 is a horizontal section taken practically on ihe -line 9 9 of Fig. 7, and Fig. 10 is a perspective Specification of Letters. Patent. Applination filed January 17,1906. semi N0 2.96.499.

Patented Sept. 11, 1906.

. sired.

portion 11' is dovetail shape "mcross-secti'oh, and its base, which is at the rear, is usually more or less concave, as is shown, particularly between the points 12 and '12., Figs. 2 and 5, or from gingivalto incisal edge but as the narrower part of the said posterior por tion of the porcelain adjoins the anterior portion thereof at the back of said anterior per-- tion an oeclusal edge 13 is formed}, and the tute occlusal surfaces 14. n the side; face of the said posterior portion 1'1 of the saidporcelain a recess or pit 1.5 is formed to receive a.

of a key 16.

The back-in B is preferably made of metal and is in the orm of a shell, its anterior portion being open and its side and posterior oritions closed, and the anterior-of the bac ing B is an exact counterpart of the posterior portion of the described facing or porcelain, and when the packing is applied to-the said facing or orcelain it adheres closely thereto. The bac ing may be of any desired thickness at shape in cross-sectio11,.and the posterior portion of the backing may be extended beyond theiincisory edge of the orcelain, forming a protection therefor, and the said posterior portion ofthe backing may be extended only porcelain, thus giving a more natural appearance to the tooth. In one side of the backing an opening 18 is made, which registers with the pit or recess 15 in the porcelain, through which opening the key 16 is passed. It will be observed that the porcelain is retained by 10 5 means of the metal environment around the body of the tooth and that the grooves forming the dovetail being in the sides of the body of the porcelain the tooth is not weakened.

The porcelain can be removed from the body 1 10 In all forms of the porcelain the posterior locking device, which device in the nature.

any point and interiorly it is always dovetail V fici'ently wide to conceal the backing, d

faces of the said posterior ortion 11 consti artially around the lingual surface 17 of the at any time by simply removing the key 16" and sliding the porcelain out from the backing in a direction continuous with the lineof the base. I

In Fi 10 I have shown a porcelain A, pro-' vided with a facing B, adapted for use in connection with a post 18, the facing consisting of a back member 19, side members 20, and a cap or cover member 21,to which the post 18 is secured, which construction is particularly adaptable Where a single" crown is to be used.

In bridgework the post is not needed.

Having thus described In invention, I

claim as new and desire to see re by Letters Patent 1 1. A denture comprising a p0v lain hav- -ing its posterior portion formed into a (loveagainst said occlusal edges, and a locking device'for the backing.

' Ina denture, a porcelain provided with a posterior portion dovetail in cross-section, the anterior portion of the said porcelain extending beyond the side faces of the posterior portion of the porcelain, one of said side faces havinga recess therein, and a backing dovetail in cross-section", which backing conforms strictly to the contour of the posterior portion of the orcelain and adheres closely thereto, the side members of the ,said backing engaging with the shoulders formedby the extension of the anterior portion of the porcelain beyond the sides of its posterior portion, one of the side members of the backing having an opening therein adapted to register with the recess in the porcelain, and a key passed through said opening into said recess.

In testimony whereof I have signed my name to this specification in the presenceof two subscribing witnesses. l

- ROBERT MEADE CRAIG. Witnesses:

W. J. ROBERTS, R. B. Loos. 

